Urban green energy presents challenges which are more difficult to meet than the needs of rural and semi-rural areas. There is simply a far greater demand for power from more people all packed in tightly together, including industry and business premises which are prolific users of electrical power, and now data storage banks which need to be constantly maintained. The unique problems of metropolitan areas are not impossible to solve, but it is likely that the solution will involve the use of land immediately outside of the area.
The first technology which usually comes to mind when people start discussing renewable energy is solar power, and this undoubtedly has the potential to provide the power for much of the energy needs of a major city. It can power domestic properties, some industrial and commercial centres, and it can also provide much of the power for rail based transit systems. Using solar power in urban areas is more difficult, as there is less roof space for every individual living in the city, but it can certainly make an impact upon the amount of electricity which has to be provided through the grid system.
The use of wind and water power is even more difficult in urban areas, but they cannot be ruled out completely. Wind power installations only have limited potential when used on buildings, partly because of the need to access to high winds, and partly because of building and noise pollution regulations. There is no reasons why wind farms cannot be used to provide power for cities, but they need to be located outside the city boundaries. The most effective wind farms are those which are located offshore, and this is a possibility for powering cities which are located on a windy coastline.
The most difficult issue of all in generating urban green energy is in powering industrial plants. There is not only a heavy demand for the electricity itself, there are also often power surges which demand the ability to dramatically increase consumption. Many industrial complexes take up a large area of space, and therefore have the potential to generate solar power from installations on the roof of extremely large buildings. As of now, solar panels would not be powerful enough to provide all of the power needs of industrial centres, but this could change in the future with far more powerful photovoltaic panels.
Houses in urban areas are able to generate electricity just as well as those in rural areas, at least by using solar panels on the roof. The amount of roof space dictates how many photovoltaic panels can be placed on top of the house, while the surrounding area dictates how much sun will actually fall on the roof. In areas of detached houses which are set some distance apart, there is no reason why an urban house should not receive as much light as most rural houses. With more powerful solar panels, it will be possible to generate enough electricity to power an entire community.
The generation of urban green energy will continue to be a difficult issue for those trying to reduce dependence upon fossil fuels. It is clear that only a part of the energy needs of a city can ever be produced within the boundaries of the metropolitan area itself, but that does not mean a city cannot effectively become self sufficient. Many cities are located near the coast, giving the possibility of powerful offshore installations to fuel most of the city’s needs. There are other cities close to desert areas where solar installations could be created. There is a potential, eventually, for all needs to be met by urban green energy.